The
Beamless Beamway of the Future

by
Olav Naess

Here
is a cross-section of the next generation beam, showing how the
wheels run in it.Thenext
generation beamway has no beam, and the next generation trains have
no wheels.

This
article is about the spear train, as mentioned in “Are Strong
Beams Needed?”. The other beamway articles on this site are
about the 2C beam: a steel beam consisting of two C-shaped
half-beams. To prevent unnecessary confusion, the alternative beamway
type – the beamless type – is described here, in a
separate article.

It
was stated about the spear train that it could manage without a beam
if it could carry along its own beam, which flew like a spear through
a sequence of rings forming a straight line, each ring on top of its
pole. The length of the spear was supposed to be more than twice the
distance between the poles.

The
first generalization is: The train can turn to the side (following a
curved alignment of rings) if the spear can bend to the sides like a
spine, but retain its stiffness vertically (and of cause not roll to
any side).

The
second generalization is: The train can also turn upwards or
downwards by replacing its stiffness with a well controlled spine
bending which doesn't yield to gravity, but strongly enforces an
adaptation to the vertical contour of the track.

For
safety reasons, only weak curvatures are permitted. This follows from
the following principle for adaptive train shape control:

The
spine is almost a spear, as it can only bend a little. This means the
radius of track curvature must be quite large, so the design is for
high-speed, long distance trains. It bends horizontally and
vertically under computer control, guided by the detected direction
to the next ring, and/or the direction data it has for this ring
position in its database. The train may of cause not fly out in the
blue if computer control or power is lost, so some simple mechanical
fallback mechanisms must ensure correct tracking, although in a more
brutal manner.

A
conventional train is here attached under a flying spear.The
total spine strength of the spear alone is likely to be too small.

This
picture shows how the rectangular “ring” on top of each
pole has a certain length, so that it can act as a guiding tube and
apply its forces to the rectangular spear in a smooth and efficient
manner. The first part of the tube is funnel-shaped in order to
correct for moderate misalignment. The first part of the spear should
be able to yield readily to this mechanical deflection, so that the
spear will be deflected reasonably smoothly. The internal walls of
the tube should also be elastically mounted. This mechanical
mechanism will hopefully be needed rarely, as the spear should be
able to aim and bend accurately enough.

Each
pole could have an air blower which sends out an air stream through
holes in the floor, the side walls, and perhaps the ceiling of the
tube while a spear is passing, so that the spear slides on a cushion
of air. (And birds would be scared away.) But a less mechanical
method would be more reliable: Maglev (magnetic levitation), and
especially the simplified version called Inductrack,
whose track magnets are simply unpowered coils in the track. The
train can certainly have a set of these coils in the beam it brings
along, and a set of electromagnets for repelling these coils will be
placed in each tube. Alternatively, there could be a short stretch of
unpowered coils in each tube, and powered coils in the spear, but
that would require a more intensive (inductive) power transfer to the
train, so that would bring us back to the previous arrangement.

First
fallback mechanism: Water is squirted out, so that the spear
aquaplanes. This could also be done from the first part of the spear.

Second
fallback mechanism: The inner walls of the tube are plated with a
special polyethylene (UHMWPE),
which is quite strong and slippery. The spear should be plated with
the same, so that it can slide quite well without any lubrication.
Using sliding contact down on the ground, would be quite unthinkable,
as it is too sensitive to disturbances from dust and debris. But at
beamway altitudes, the conditions are far better.

When
the train now is ready to slide, it doesn't mean it will really be
doing it, but rather that it now can fly on a thin air cushion or a
magnetic field with greater safety.

A
spear passing through the guiding tube

The angularity of the
profile will hopefully reduce the leakage of air to the wrong
surface. The red dots indicate where safety wires to the next
tube may be attached.Such wires should be made of carbon fibers,
so that they don't bend much down in the middle. They may not be much
touched by spears on straight stretches. In curves, it may be better
to replace them with beams measuring e.g. 3x25 cm.

Under
the tube, we see a linear motor (described in the main BeamTech
article). These will be omitted if maglev is used, and it can
give a horizontal force suitable for propulsion. The row of permanent
magnets is in these pictures shown hanging like sausages between the
suspension rods. But it may be better to replace the suspension rods
with vertical plates which are effectively a downwards extension of
the spear, thus improving the strength of the spear. This plate
system should have slots for the magnets. It should also be able to
expand where it passes through the slit in the bottom of the guiding
tube, so that a high friction zone here along the plates is pressed
against a corresponding high friction zone inside the slit. This will
make a quite efficient emergency brake. The ordinary beamway will be
a stronger structure in this respect, as many poles are firmly
connected. A spear train will engage two poles during an emergency
brake, in addition to getting force from some poles behind if there
are safety wires.

Laser
beams should be sent from tube to tube – to detect accidental
misalignment.